I. Field
The present disclosure relates generally to communication, and more specifically to techniques for transmitting data in a wireless communication network.
II. Background
A wireless multiple-access communication network can concurrently communicate with multiple terminals on the downlink and uplink. The downlink (or forward link) refers to the communication link from the base stations to the terminals, and the uplink (or reverse link) refers to the communication link from the terminals to the base stations. Multiple terminals may simultaneously receive signaling and data on the downlink and/or transmit signaling and data on the uplink. This may be achieved by multiplexing the transmissions to be orthogonal to one another (e.g., on the downlink) and/or by controlling the transmit power of each transmission to achieve a desired received signal quality for the transmission while reducing interference to other transmissions (e.g., on the uplink).
A base station may transmit data to a number of terminals within its coverage area. To improve performance, it is desirable for the base station to be able to schedule a variable number of terminals in each transmission time interval (TTI). A TTI is the smallest unit of time over which a data packet can be scheduled for transmission to one or more terminals. To further improve performance, the base station may utilize multiple antennas to transmit multiple data streams simultaneously to the terminals. These data streams are distorted by the radio environment and act as interference to one other at each recipient terminal. The interference hinders each terminal's ability to recover the data stream(s) sent for the terminal.
There is therefore a need in the art for techniques to efficiently transmit data to multiple terminals.